If I'm throwing a big hunk of meat in the oven, the meat starts out too cold. Any increase in its temperature is a welcome improvement that brings it closer to being ready to eat. Why not throw it in the oven while the oven's preheating?

It's easy to get away with this for anything that bakes for an hour or more, especially for fatty or sauce-coated meats where dryness is not a concern. I wish recipes would call for these foods to be thrown into a cold oven.

Obviously, recipes for leavened breads are very sensitive and might not take kindly to this change.

If I'm throwing a big hunk of meat in the oven, the meat starts out too cold. Any increase in its temperature is a welcome improvement that brings it closer to being ready to eat. Why not throw it in the oven while the oven's preheating?

It's easy to get away with this for anything that bakes for an hour or more, especially for fatty or sauce-coated meats where dryness is not a concern. I wish recipes would call for these foods to be thrown into a cold oven.

Obviously, recipes for leavened breads are very sensitive and might not take kindly to this change.

Depends on recipe and medium used. Cold oven, cold clay pot. Solid copper, tin lined fry pan is cold to begin with. Usually a pan that has been preheated for 2 minutes or so is less likely for your food to stick.

did you see the MythBuster's episode where they stuck their fingers in molten lead?
(this is not a joke,,,,)

oversimplified,,,,
if you plop cold meat into a cold pan, as it warms up the liquids & proteins start to 'ooze' out and bake themselves onto the pan.

if you plop a chunk of meat into a pre-heated / hot pan the moisture turns to steam - the same effect as with the molten lead - this layer provides _short term_ 'protection' - the steam makes for a small 'anti-friction / non-contact' layer until the meat surfaces sear and 'seal off' - becoming 'not stuck'

now, reality is slightly in-between. you may have heard the advice - put meat in the pan and leave it alone until it "releases" - releases means it un-sticks itself from the pan and you can easily move/turn/flip/whatever. also applies to a number of other foodstuffs.

How much of a difference does this make? As a college student, I do a lot of "brown beef, add sauce" kind of things (Little ashamed of myself now...) Should I worry about preheating my pan for that situation, or just save it for frying chicken, doing steak or pork, or the like?

It all depends on what you are cooking. Remember that when the oven is being brought up to temperature, in most cases both the upper and lower heating elements come on and stay on at their highest level the until the oven is at the temperature you set.

This means that whatever you put in the oven is subjected to much higher sustained direct heat on the top and the bottom than it would normally be in a preheated oven. Also, if you put a big hunk of cold meat in the oven before turning it on, it is going to take even longer before the probe in the oven reads the target temperature.

Certainly ovens cruise up and down regarding temperature, and the burners turn on and off as this happens, and so whatever you are roasting or baking is occasionally subjected to high direct heat, but for a much shorter duration than during preheating. Also, not to get into physics too much here, but whatever you are cooking is going to react differently to direct heat if the sides are already warm than they will if the whole thing is cold. In a roast, for instance, the juices will have somewhere to go aside from just bubbling out the top and bottom. Think of it this way: When you cut a raw steak, how much of the blood and juices run out? And how much run out when you cut one that has just been cooked to medium rare?

That said, I wouldn't worry about it too much with your average smaller roast beef, but I would certainly want to preheat my oven before baking bread, cookies, a cake, or in fact any sort of baking like this. Also, with wet cooking methods, like pot roast, no big deal. and in the case of most meats, I don't think sticking is really the issue. Unless they are ridiculously fat-free, they will release by the time they are done. However, I wouldn't make it a point of pride to "never" preheat the oven. There really are some times when it is advisable.

When i make Mac and Cheese for example i put the stuff in the pan STRAIGHT AWAY instead of waiting for the water to boil..

Dude, you can certainly do this, and have it turn out quite well, if you have already done the experimentation, and figured out exactly how long it takes from a cold pot of water to the finished product. However, this can allow a variable you may not have factored in, and that is the temperature of your tap water. In the summer, chances are your "cold" tap water is a good deal warmer than it is in the winter, and so your water may take longer to boil in the colder months. Therefore your pasta may be overdone in the summer, and underdone in the winter given exactly the same time on the burner.

The thing about boiling water is that it is a constant. It is always the same temperature at a given altitude, (yes, you sticklers, it will change due to barometric pressure, but it is still pretty danged close) so if you wait for the water to boil before adding the pasta, the cooking time will always be the same.